Blown fuses detecting system - uses photocells to sense operation of neon lamps across fuses

摘要

The apparatus for the central control and detection of blown fuses includes at a central location a neon warning lamp supplied by a photoelectric cell with a variable resistance. This cell is placed in the dark and is sensitive to an assembly of neon lamps, each supplied by a circuit linked to the terminals of one of the fuses of the installations. The photoelectric cell also includes a test lamp operated via a pushbutton positioned at the central location. This checks the operation of the system.